print('字典')
word = {'a':'1','b':'2','c':'3'}

print(word.get('a'))


word1 = {}
word1 = word1.fromkeys(range(20),'a')

for eachK in word1:
    print(eachK)

for eachV in word1.values():
    print(eachV)

for eachI in word1.items():
    print(eachI)

print(word1.get(3))
# print(word1)